If your REALLY gonna be the spotter, then the most important thing is to make sure that the trucks underside dosen't hit anywhere, in other words, make blackdog climbs the hi stuff, so his suspension and drivetrain doesn't get caught up on rocks or branches! If your "feeling out" a mud hole, ALWAYS add at least 8" to whatever depth you feel with a stick! Believe me 8" MINIMUM!
That help at all?